Clin Rheumatol DOI 10.1007/s10067-015-2922-1
ORIGINAL ARTICLE
Serum microRNAs as Potential Biomarkers of Juvenile Idiopathic Arthritis Yasuko Kamiya 1 & Jun-ichi Kawada 1 & Yoshihiko Kawano 1 & Yuka Torii 1 & Shinji Kawabe 2 & Naomi Iwata 2 & Yoshinori Ito 1
Received: 24 January 2015 / Revised: 17 March 2015 / Accepted: 20 March 2015 # International League of Associations for Rheumatology (ILAR) 2015
Abstract MicroRNAs (miRNAs) are non-coding RNAs that regulate gene expression of targeted mRNAs, which are important in the pathogenesis of autoimmune diseases. MiRNAs may have the potential to serve as biomarkers of disease. We evaluated serum levels of selected miRNAs and their associations with disease activity in juvenile idiopathic arthritis (JIA). Sera and peripheral blood leukocytes were collected from patients with JIA (8 systemic onset, 16 polyarthritis) and healthy controls. Levels of miR-16, miR-132, miR146a, miR-155, and miR-223 were quantified. Levels of miR-223 in sera were significantly higher in patients in the active phase of systemic onset JIA than in controls. MiRNAs of peripheral blood leukocytes did not exhibit any difference between patients with JIA and controls. In both systemic onset JIA and polyarthritis patients, levels of miR-223 and miR-16 correlated with erythrocyte sedimentation rate and matrix metalloproteinase-3, respectively. MiR-146a and miR-223 in polyarthritis showed correlations with matrix metalloproteinase-3. Expressions of miRNAs were altered in patients with JIA. Serum levels of miR-223 may be a potential disease biomarker. Investigation of miRNAs could be helpful in understanding the pathogenesis of JIA and could aid in the identification of additional disease biomarkers.
* Yoshinori Ito [email protected] 1
Department of Pediatrics, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan
2
Department of Infection and Immunology, Aichi Children’s Health and Medical Center, 1-2 Osakada Morioka-cho, Obu, Aichi 474-8710, Japan
Keywords Biological agents . Juvenile idiopathic arthritis . micro RNAs . miR-146 . miR-155
Introduction Juvenile idiopathic arthritis (JIA) is the most common rheumatic disease in children and one of the more common chronic illnesses of childhood. JIA represents a heterogeneous group of disorders that share the clinical manifestation of arthritis occurring in children younger than 16 years [1]. Most patients with JIA are classified into three subtypes based on associated symptoms and the number of joints involved: systemic onset, oligoarthritis, or polyarthritis. The recent introduction of biological agents such as tumor necrosis factor-α inhibitors and interleukin-6 inhibitors has improved the prognosis of JIA, but persistently active JIA still represents a major therapeutic challenge [2–4]. The cause and pathogenesis of JIA are poorly understood, but one of the hallmarks of the pathology of JIA is the expansion of inflamed synovial tissue, or pannus, which is also seen in patients with adult rheumatoid arthritis (RA). In childhood, rheumatoid factor (RF)-positive polyarticular JIA is considered to be the equivalent of adult RF-positive RA [1]. As in adults, substantial proportions of patients with RF-positive polyarthritis have circulating antibodies against cyclic citrullinated peptide [5]. On the other hand, systemic onset JIA is distinct from other subtypes, and onset in adults (known as adult-onset Still’s disease) is rare. Several studies have shown that patients with systemic onset JIA have a different inflammatory profile from patients with other JIA subtypes, and this profile is characterized by overproduction of interleukin-6 and interleukin-18 [6–8]. Recent advances in our understanding of the role of the innate immune system in
Clin Rheumatol
the pathogenesis of systemic JIA lead to some thoughts about whether to consider systemic onset JIA an autoinflammatory disease rather than an autoimmune disease [9]. In addition to cytokines, S100 proteins that are released by activated phagocytes exhibit strong proinflammatory activities. It has been shown that serum concentrations of S100 proteins correlate with inflammation and can be used as biomarkers for disease activity and treatment response in JIA [10, 11]. MicroRNAs (miRNAs) are short single-stranded non-coding RNAs involved in the post-transcriptional regulation of gene expression [12, 13]. Altered expression of miRNAs has been described under various pathological conditions, including cancer and autoimmune diseases [14, 15]. As miRNAs are stably present in cell-free forms in body fluids, and because circulating miRNAs have been shown to have signatures related to tumor classification and disease progression, they are becoming new biomarker candidates for the diagnosis and prognosis of various diseases [16, 17]. The first evidence for miRNAs playing a role in RA emerged in 2007, and since then, abnormal expression of miR-16, miR-132, miR-146a, miR-155, and miR-223 has been documented, and most of these miRNAs are upregulated in different sources. Previous studies have shown that the expressions of several miRNAs are dysregulated in immune cells or inflamed joints of patients with RA [18–22]. Furthermore, levels of miR-16, miR-146a, and miR-155 have been found to be upregulated in the peripheral blood of patients with RA, and miR-16 and miR-146a levels are higher in patients with active rather than inactive RA [23, 24]. These miRNAs might reflect the pathological state of tissues and could serve as potential biomarkers of disease activity. Although circulating miRNAs have been investigated and used as novel biomarkers in various autoimmune and autoinflammatory diseases, they have not been evaluated in patients with JIA. As stated above, JIA and RA share the same clinical features and pathological changes [1]. Therefore, the expression of miRNAs might be associated with the pathogenesis of JIA. In this study, we examined levels of five miRNAs (miR-16, miR-132, miR-146a, miR-155, and miR233) in sera and the expression levels of these miRNAs in peripheral blood leukocytes (PBLs) from patients with JIA to investigate the potential use of these miRNAs as biomarkers for disease activity.
Methods Patients and samples Ethical approval for the use of clinical specimens was granted by the Institutional Review Board of Nagoya University Hospital and Aichi Children’s Health and Medical Center. Informed consent was obtained from all patients or their
guardians. Eight patients with systemic onset JIA and 16 with polyarthritis, including 7 patients with RF-positive disease, who fulfilled the International League of Association for Rheumatology classification criteria were included in the study. Clinical characteristics and laboratory findings are shown in Table 1. BActive phase of JIA^ was defined as the presence of related symptoms such as fever (>38 °C) and/or active joints, while BInactive phase of JIA^ was defined as the absence of symptoms with no elevation of C-reactive protein (CRP) (
ORIGINAL ARTICLE
Serum microRNAs as Potential Biomarkers of Juvenile Idiopathic Arthritis Yasuko Kamiya 1 & Jun-ichi Kawada 1 & Yoshihiko Kawano 1 & Yuka Torii 1 & Shinji Kawabe 2 & Naomi Iwata 2 & Yoshinori Ito 1
Received: 24 January 2015 / Revised: 17 March 2015 / Accepted: 20 March 2015 # International League of Associations for Rheumatology (ILAR) 2015
Abstract MicroRNAs (miRNAs) are non-coding RNAs that regulate gene expression of targeted mRNAs, which are important in the pathogenesis of autoimmune diseases. MiRNAs may have the potential to serve as biomarkers of disease. We evaluated serum levels of selected miRNAs and their associations with disease activity in juvenile idiopathic arthritis (JIA). Sera and peripheral blood leukocytes were collected from patients with JIA (8 systemic onset, 16 polyarthritis) and healthy controls. Levels of miR-16, miR-132, miR146a, miR-155, and miR-223 were quantified. Levels of miR-223 in sera were significantly higher in patients in the active phase of systemic onset JIA than in controls. MiRNAs of peripheral blood leukocytes did not exhibit any difference between patients with JIA and controls. In both systemic onset JIA and polyarthritis patients, levels of miR-223 and miR-16 correlated with erythrocyte sedimentation rate and matrix metalloproteinase-3, respectively. MiR-146a and miR-223 in polyarthritis showed correlations with matrix metalloproteinase-3. Expressions of miRNAs were altered in patients with JIA. Serum levels of miR-223 may be a potential disease biomarker. Investigation of miRNAs could be helpful in understanding the pathogenesis of JIA and could aid in the identification of additional disease biomarkers.
* Yoshinori Ito [email protected] 1
Department of Pediatrics, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan
2
Department of Infection and Immunology, Aichi Children’s Health and Medical Center, 1-2 Osakada Morioka-cho, Obu, Aichi 474-8710, Japan
Keywords Biological agents . Juvenile idiopathic arthritis . micro RNAs . miR-146 . miR-155
Introduction Juvenile idiopathic arthritis (JIA) is the most common rheumatic disease in children and one of the more common chronic illnesses of childhood. JIA represents a heterogeneous group of disorders that share the clinical manifestation of arthritis occurring in children younger than 16 years [1]. Most patients with JIA are classified into three subtypes based on associated symptoms and the number of joints involved: systemic onset, oligoarthritis, or polyarthritis. The recent introduction of biological agents such as tumor necrosis factor-α inhibitors and interleukin-6 inhibitors has improved the prognosis of JIA, but persistently active JIA still represents a major therapeutic challenge [2–4]. The cause and pathogenesis of JIA are poorly understood, but one of the hallmarks of the pathology of JIA is the expansion of inflamed synovial tissue, or pannus, which is also seen in patients with adult rheumatoid arthritis (RA). In childhood, rheumatoid factor (RF)-positive polyarticular JIA is considered to be the equivalent of adult RF-positive RA [1]. As in adults, substantial proportions of patients with RF-positive polyarthritis have circulating antibodies against cyclic citrullinated peptide [5]. On the other hand, systemic onset JIA is distinct from other subtypes, and onset in adults (known as adult-onset Still’s disease) is rare. Several studies have shown that patients with systemic onset JIA have a different inflammatory profile from patients with other JIA subtypes, and this profile is characterized by overproduction of interleukin-6 and interleukin-18 [6–8]. Recent advances in our understanding of the role of the innate immune system in
Clin Rheumatol
the pathogenesis of systemic JIA lead to some thoughts about whether to consider systemic onset JIA an autoinflammatory disease rather than an autoimmune disease [9]. In addition to cytokines, S100 proteins that are released by activated phagocytes exhibit strong proinflammatory activities. It has been shown that serum concentrations of S100 proteins correlate with inflammation and can be used as biomarkers for disease activity and treatment response in JIA [10, 11]. MicroRNAs (miRNAs) are short single-stranded non-coding RNAs involved in the post-transcriptional regulation of gene expression [12, 13]. Altered expression of miRNAs has been described under various pathological conditions, including cancer and autoimmune diseases [14, 15]. As miRNAs are stably present in cell-free forms in body fluids, and because circulating miRNAs have been shown to have signatures related to tumor classification and disease progression, they are becoming new biomarker candidates for the diagnosis and prognosis of various diseases [16, 17]. The first evidence for miRNAs playing a role in RA emerged in 2007, and since then, abnormal expression of miR-16, miR-132, miR-146a, miR-155, and miR-223 has been documented, and most of these miRNAs are upregulated in different sources. Previous studies have shown that the expressions of several miRNAs are dysregulated in immune cells or inflamed joints of patients with RA [18–22]. Furthermore, levels of miR-16, miR-146a, and miR-155 have been found to be upregulated in the peripheral blood of patients with RA, and miR-16 and miR-146a levels are higher in patients with active rather than inactive RA [23, 24]. These miRNAs might reflect the pathological state of tissues and could serve as potential biomarkers of disease activity. Although circulating miRNAs have been investigated and used as novel biomarkers in various autoimmune and autoinflammatory diseases, they have not been evaluated in patients with JIA. As stated above, JIA and RA share the same clinical features and pathological changes [1]. Therefore, the expression of miRNAs might be associated with the pathogenesis of JIA. In this study, we examined levels of five miRNAs (miR-16, miR-132, miR-146a, miR-155, and miR233) in sera and the expression levels of these miRNAs in peripheral blood leukocytes (PBLs) from patients with JIA to investigate the potential use of these miRNAs as biomarkers for disease activity.
Methods Patients and samples Ethical approval for the use of clinical specimens was granted by the Institutional Review Board of Nagoya University Hospital and Aichi Children’s Health and Medical Center. Informed consent was obtained from all patients or their
guardians. Eight patients with systemic onset JIA and 16 with polyarthritis, including 7 patients with RF-positive disease, who fulfilled the International League of Association for Rheumatology classification criteria were included in the study. Clinical characteristics and laboratory findings are shown in Table 1. BActive phase of JIA^ was defined as the presence of related symptoms such as fever (>38 °C) and/or active joints, while BInactive phase of JIA^ was defined as the absence of symptoms with no elevation of C-reactive protein (CRP) (
